/****************************************************************************
**
** Copyright (C) 2017 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of Qt 3D Studio.
**
** $QT_BEGIN_LICENSE:GPL$
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** accordance with the commercial license agreement provided with the
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** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3 or (at your option) any later version
** approved by the KDE Free Qt Foundation. The licenses are as published by
** the Free Software Foundation and appearing in the file LICENSE.GPL3
** included in the packaging of this file. Please review the following
** information to ensure the GNU General Public License requirements will
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****************************************************************************/

#include "q3dssceneelement_p.h"
#include "q3dspresentation_p.h"
#include "q3dscommandqueue_p.h"

#include <QtCore/qdebug.h>
#include <QtCore/qsettings.h>
#include <QtCore/qcoreapplication.h>

QT_BEGIN_NAMESPACE

Q3DSSceneElement::Q3DSSceneElement(QObject *parent)
    : Q3DSElement(new Q3DSSceneElementPrivate(this), nullptr, QString(), parent)
{
}

Q3DSSceneElement::Q3DSSceneElement(const QString &elementPath, QObject *parent)
    : Q3DSElement(new Q3DSSceneElementPrivate(this), nullptr, elementPath, parent)
{
}

Q3DSSceneElement::Q3DSSceneElement(Q3DSPresentation *presentation, const QString &elementPath,
                                   QObject *parent)
    : Q3DSElement(new Q3DSSceneElementPrivate(this), presentation, elementPath, parent)
{

}

Q3DSSceneElement::~Q3DSSceneElement()
{
}

int Q3DSSceneElement::currentSlideIndex() const
{
    Q_D(const Q3DSSceneElement);
    return d->m_currentSlideIndex;
}

int Q3DSSceneElement::previousSlideIndex() const
{
    Q_D(const Q3DSSceneElement);
    return d->m_previousSlideIndex;
}

QString Q3DSSceneElement::currentSlideName() const
{
    Q_D(const Q3DSSceneElement);
    return d->m_currentSlideName;
}

QString Q3DSSceneElement::previousSlideName() const
{
    Q_D(const Q3DSSceneElement);
    return d->m_previousSlideName;
}

void Q3DSSceneElement::setCurrentSlideIndex(int currentSlideIndex)
{
    Q_D(Q3DSSceneElement);
    if (d->m_viewerApp) {
        const QByteArray path(d->m_elementPath.toUtf8());
        d->m_viewerApp->GoToSlideByIndex(path, currentSlideIndex + 1);
    } else if (d->m_commandQueue) {
        d->m_commandQueue->queueCommand(d->m_elementPath, CommandType_GoToSlide,
                                            int(currentSlideIndex + 1));
    } else {
        // Store desired slide until we have either app or queue. Only name or index can be set.
        d->m_initialSlideIndex = currentSlideIndex + 1;
        d->m_initialSlideName.clear();
    }
}

void Q3DSSceneElement::setCurrentSlideName(const QString &currentSlideName)
{
    Q_D(Q3DSSceneElement);
    if (d->m_viewerApp) {
        const QByteArray path(d->m_elementPath.toUtf8());
        const QByteArray name(currentSlideName.toUtf8());
        d->m_viewerApp->GoToSlideByName(path, name);
    } else if (d->m_commandQueue) {
        d->m_commandQueue->queueCommand(d->m_elementPath, CommandType_GoToSlideByName,
                                            currentSlideName);
    } else {
        // Store desired slide until we have either app or queue. Only name or index can be set.
        d->m_initialSlideName = currentSlideName;
        d->m_initialSlideIndex = 0;
    }
}

void Q3DSSceneElement::goToSlide(bool next, bool wrap)
{
    Q_D(Q3DSSceneElement);
    d->goToSlide(next, wrap);
}

void Q3DSSceneElement::goToTime(float time)
{
    Q_D(Q3DSSceneElement);
    d->goToTime(time);
}

Q3DSSceneElementPrivate::Q3DSSceneElementPrivate(Q3DSSceneElement *parent)
    : Q3DSElementPrivate(parent)
    , m_currentSlideIndex(0)
    , m_previousSlideIndex(0)
    , m_initialSlideIndex(0)
    , m_slideInfoRequestPending(false)
{
}

Q3DSSceneElementPrivate::~Q3DSSceneElementPrivate()
{
}

void Q3DSSceneElementPrivate::handleSlideEntered(int index, const QString &name)
{
    Q_Q(Q3DSSceneElement);

    // Initializing presentation will report slide entered for the scenes on the default slide
    // of the presentation even if user has specified different initial slides.
    // Since we don't have robust error reporting mechanism from the viewerapp,
    // we cannot simply ignore these initial enters, as there is no guarantee the slide
    // user wants even exists.

    // We ignore the slide exited signals and rely on stored previous slide data
    // to avoid excessive signaling on slide changes.
    bool notifyCurrent = m_currentSlideIndex != index;
    bool notifyPrevious = m_previousSlideIndex != m_currentSlideIndex;

    // Since child (i.e. component) slides always get enter event when parent slide is entered,
    // it is possible that current and previous slides are the same. This feels bit odd, but is
    // technically correct, as the last time we got enter, the same slide was made current.
    // It also matches the internal m_viewerApp logic for previous slides.
    m_previousSlideIndex = m_currentSlideIndex;
    m_previousSlideName = m_currentSlideName;
    m_currentSlideIndex = index;
    m_currentSlideName = name;

    if (notifyPrevious) {
        Q_EMIT q->previousSlideIndexChanged(m_previousSlideIndex);
        Q_EMIT q->previousSlideNameChanged(m_previousSlideName);
    }

    if (notifyCurrent) {
        Q_EMIT q->currentSlideIndexChanged(m_currentSlideIndex);
        Q_EMIT q->currentSlideNameChanged(m_currentSlideName);
    }
}

void Q3DSSceneElementPrivate::goToSlide(bool next, bool wrap)
{
    if (m_presentation)
        m_presentation->q_ptr->goToSlide(m_elementPath, next, wrap);
    else
        qWarning() << __FUNCTION__ << "Element is not registered to any presentation!";
}

void Q3DSSceneElementPrivate::goToTime(float time)
{
    if (m_presentation)
        m_presentation->q_ptr->goToTime(m_elementPath, time);
    else
        qWarning() << __FUNCTION__ << "Element is not registered to any presentation!";
}

void Q3DSSceneElementPrivate::setViewerApp(Q3DSViewer::Q3DSViewerApp *app)
{
    Q_Q(Q3DSSceneElement);

    if (app || m_viewerApp) {
        m_currentSlideIndex = 0;
        m_currentSlideName.clear();
        m_previousSlideIndex = 0;
        m_previousSlideName.clear();
    }

    Q3DSElementPrivate::setViewerApp(app);

    if (m_viewerApp) {
        const QByteArray path(m_elementPath.toUtf8());
        m_viewerApp->GetSlideInfo(path, m_currentSlideIndex, m_previousSlideIndex,
                                  m_currentSlideName, m_previousSlideName);

        // If user has set current slide before viewer app has been set for the first time,
        // we will switch to the desired slide after we initialize.
        if (m_initialSlideIndex != 0)
            q->setCurrentSlideIndex(m_initialSlideIndex - 1);
        else if (!m_initialSlideName.isEmpty())
            q->setCurrentSlideName(m_initialSlideName);

        m_initialSlideIndex = 0;
        m_initialSlideName.clear();
    }
}

void Q3DSSceneElementPrivate::setCommandQueue(CommandQueue *queue)
{
    Q_Q(Q3DSSceneElement);

    if (queue || m_commandQueue) {
        m_currentSlideIndex = 0;
        m_currentSlideName.clear();
        m_previousSlideIndex = 0;
        m_previousSlideName.clear();
    }
    Q3DSElementPrivate::setCommandQueue(queue);

    if (m_commandQueue) {
        m_commandQueue->queueCommand(m_elementPath, CommandType_RequestSlideInfo);
        m_slideInfoRequestPending = true;
        // If user has set current slide before the queue has been set for the first time,
        // we will switch to the desired slide after we initialize.
        if (m_initialSlideIndex != 0)
            q->setCurrentSlideIndex(m_initialSlideIndex - 1);
        else if (!m_initialSlideName.isEmpty())
            q->setCurrentSlideName(m_initialSlideName);

        m_initialSlideIndex = 0;
        m_initialSlideName.clear();
    }
}

void Q3DSSceneElementPrivate::requestResponseHandler(CommandType commandType, void *requestData)
{
    switch (commandType) {
    case CommandType_RequestSlideInfo: {
        QVariantList *response = reinterpret_cast<QVariantList *>(requestData);
        if (m_slideInfoRequestPending) {
            m_slideInfoRequestPending = false;

            m_previousSlideIndex = response->at(1).toInt();
            m_previousSlideName = response->at(3).toString();

            handleSlideEntered(response->at(0).toInt(), response->at(2).toString());
        }
        delete response;
        break;
    }
    default:
        Q3DSElementPrivate::requestResponseHandler(commandType, requestData);
        break;
    }
}

QT_END_NAMESPACE